Ships&#39; gravity davits for launching lifeboats from stowed positions between decks



Apnl 23, 1963 M. SCHAT 3,086,227

SHIPS GRAVITY DAVITS FOR LAUNCHING LIFBBOATS FROM STOWED POSITIONS BETWEEN DECKS Filed June 6, 1960 2 Sheets-Sheet 1 IIIII'IIIIIIII'IIIIII'IIII'I'I I INVENTOR ala L- 5mm April 23, 1963 M. L. SCHAT 3,086,227

SHIPS GRAVITY DAVITS FOR LAUNCHING LIFEBOATS FROM STOWED POSITIONS BETWEEN DECKS Filed June 6, 1960 2 Sheets-Sheet 2 a an r I r S. I E o l 2 0/ E Q Q a o --a INVENTOR United States Patent Office 3,086,227 Patented Apr. 23, 1963 SHIPS GRAVITY DAVITS FOR LAUNCHING LIFE- BOATS FROM STOWED POSITIONS BETWEEN DECKS Martinns Leendert Schat, 13 Aldenham Ave, Radlett, England Filed June 6, 1960, Ser. No. 34,008 Claims priority, application Great Britain June 8, 1959 1 Claim. (Cl. 9-36) This invention relates to lifeboat gravity davits for ships, and more particularly to the type of gravity davits used for launching lifeboats from stowed positions between decks.

According to this invention, the davit arm is suspended by means of two suspending arms (or sets of two suspending arms engaging the davit arm. In each set of suspending arms, one of the arms is shaped as a boomerang and is hinged at one end to the upper deck adjacent the outboard edge thereof and to the davit arm at a location close to the keel of the boat in its stowed position. The second arm of each set is hinged at one end thereof to the upper deck an appreciable distance inward from said edge and to the davit arm at a point spaced from the lower hinge of the first suspending arm and substantially in a vertical line with the connection of said second arm to the upper deck. The suspending arms are so arranged as to cause the d vit arm, when swung outwards, to perform a translatory and rotary movement such that the lifeboat moves along an outwardly and downwardly path which is outside the clear space which is defined by the lifeboat and davit with respect to the lower deck when the lifeboat is in stowed position. The suspending arms enable the davit arm and lifeboat to swing outboardly by the weight of the lifeboat. Thus the gravity force on the lifeboat operates to swing it outboard. The gravity force is selectively balanced by the fall or cable supporting the lifeboat.

As compared with known davits of the type referred to, the davit according to the invention has, inter alia, the following advantages:

(1) The frictional resistance of the arm during its outward and inward movement is kept to a minimum, as distinguished from that of an arm provided with rollers or the like running in a trackway.

(2) Owing to the combined translatory and rotary movement of the arm, the usual suspension hook or tusk carried by the davit head may be rigidly secured thereto, so as to render superfluous a rather complicated device for locking the said hook when the same is pivotally mounted to the head.

(3) The boat in its stowed position is supported by the davit arm and cannot swing inboardly when the ship is rolling.

In order that our invention may be fully understood by those skilled in the art, reference is made to the accompanying drawing, wherein:

FIG. 1 is a front view of a life boat and of a davit arm suspended between decks in the manner stated hereinbefore, in stowed position,

FIG. 2 is a similar view with the boat and the davit arm in outboard position, and

FIG. 3 is a front view corresponding to that shown in FIG. 1 but illustrating a veranda on the lower deck right below the stowed boat.

In FIG. 1 the numeral 4 indicates the upper deck, 5 the railing thereof, 6 the lower deck, 7 the railing there of, 8 the lifeboat, 9 the davit arm, 10 the head sheave of the arm, 11 the suspension hook or tusk" of the arm, 12 the fall for handling the boat, 13 a. pulley for guiding the fall, 14 the boomerang-shaped first suspending arm, 15 the chock secured to the davit arm supporting the boat, 16 the pivot through which said first suspending arm is connected to the upper deck, 17 the keel support on the davit arm, 18 the pivot through which said first suspending is arm connected to the davit arm, 19 the second suspending arm, 20 the pivot through which the same is connected to the upper deck, 21 the pivot through which the same is connected to the davit arm, the latter pivot being at a level immediately below the lifeboat when the latter is in the stowed position and numeral 22 represents a balcony.

FIG. 2 illustrates the boat and the davit arm in outboard position. The various parts shows therein have been indicated by the same reference numerals as in FIG. 1, so that further description thereof may be dispensed with.

FIG. 3 is identical with FIG. 2 as far as the davit construction and the positions of the various parts are concerned, but illucidates the free deck space right below the stowed boat by the spacious veranda 23 having window pan-es 24. It further shows a space 25 below the balcony 22 for accommodating ventilating ducts.

What I claim is:

A gravity davit for a lifeboat of a ship, the ship having upper and lower decks in spaced relation, the davit comprising: a davit arm having a free end adapted for supporting the lifeboat in a first position in the space between an upper and lower deck of the ship, the davit arm being of curved shape for accommodating the lifeboat and preventing inward movement thereof, two suspending arms pivotally connected to the upper deck for supporting the davit arm, one of said suspending arms being of curved shape and being pivotally connected at an end thereof to the upper deck at a location outboardly with respect to the lifeboat with the latter in said first position, said one arm having an end opposite to the first said end thereof and pivotally coupled to the davit arm at a location adjacent the free end of the davit arm, the other of said suspending arms having one end pivotally connected to the upper deck at a loca tion inboardly with respect to the lifeboat with the latter in said first position, said other suspending arm having an end opposite the first said end thereof and pivotally connected to said davit arm, such that the pivotal connections of said other suspending arm are substantially vertically aligned, said other suspending arm being connected to said davit arm at a level immediately below the lifeboat with the latter in said first position such that, upon swinging of the davit arm outboardly, the lifeboat and davit move along an outboard downwardly path in spaced relation from the lower deck and outside a clear space defined by the lifeboat and davit with the lower deck when the lifeboat is in the first position.

References Cited in the file of this patent UNITED STATES PATENTS 2,929,081 Taylor Mar. 22, 1960 FOREIGN PATENTS 269,136 Great Britain Nov. 17, 1927 338,686 Great Britain Nov. 27, 1930 481,587 France Sept. 28, 1916 666,703 Great Britain Feb. 20, 1952 939,428 Germany Feb. 23, 1956 

